Reviewed-by: Trust Me

* Convert dots in filenames to underscores in header guards
* Don't indent closing namespaces in source file
* Consistent empty line placement

Fixes: Introduce a cpp settingspage containing file naming conventions (lower case and suffixes). Reorder VCS settings pages.

Task: 241959, 248085

RevBy: Optics/Naming checked by con
Details: Give IOptionPage an id() to differentiate from trName(). Make showOptionsDialog return a bool (applied) and give it an optional parent. Change Cpp and form class wizards, give them a Configure... button to change those settings.

Use _HPP for example for .hpp files, for example. Based on simply
putting the chosen extension in uppercase.

Task: 237390
Details: Add 'allowDirectories' property to the widgets involved.